Air moving unit



May 22, 1962 SIMMONS AIR MOVING UNI T 2 Sheets-Sheet 1 Filed NOV. 1,1954 INVENTOR. Lmvc' L. S/MMo/Vs M/ TH, 01mm 14 0775 L. L. SIMMONS AIRMOVING UNIT May 22, 1962 2 Sheets-Sheet 2 Filed NOV. 1, 1954 IN V ENTOR. Z mvcE Z S IMMONS 5/1/ 7H, 0450M lforrs United States Patent Office3,035,760 Patented May 22, 1952 3,035,760 AIR MOVING UNIT Lance LovejoySimmons, Detroit, Mich., assignor, by mesne assignments, to AmericanRadiator & Standard Sanitary Corporation, New York, N.Y., a corporationof Delaware Filed Nov. 1, 1954, Ser. No. 465,898 1 Claim. (Cl. 230-125)The present invention relates to an air moving uni and in particular tosuch a unit which includes a peripheral line flow fan of the centrifugaltype, said unit being particularly but not exclusively adapted for usein an air conditioner.

Peripheral line flow fans are well known in the art. Such fans arecentrifugal fans of the type wherein air is drawn in along the peripheryand also discharged along the periphery. Such a fan is shown in PatentNo. 1,838,- 169, dated Dec. 29, 1931, issued to Edward L. Anderson.

All fans generate in the fan wheel velocity pressure and static pressurein varying ratios. When a forwardly curved fan blade is utilized, theratio of velocity pressure to static pressure has in the past beenrelatively high, and means must be provided for effectively convertingvelocity pressure to static pressure. When a backward curved blade isutilized, the ratio between velocity pressure and static pressure isquite low, and conversion of velocity pressure to static pressure is notas critical. The blade designs between these two extremes provide ratiosof velocity pressure to static pressure which vary accordingly.

In many applications of a line flow fan, particularly one with aforwardly curved blade design, the overall construction such as shown inthe Anderson patent has not produced optimum results. This isparticularly true in high pressure systems. The air moving device of thepresent invention provides a fan chamber and duct which permits the useof a forwardly curved fan blade while still effectively convertingvelocity pressure to static pressure to produce a suitable ratio.

It is an object of the present invention to provide an air moving unitwith a centrifugal fan of the above-mentioned type which is capable ofmoving more air per unit of power input than has heretofore beenconsidered possible.

It is another object of the present invention to provide a fan chamberfor an air moving unit which is so constructed and arranged as to aid inobtaining maximum efficiency of the fan operation.

It is a further object of the present invention to provide an air movingunit including a chamber which efficiently handles air movement with aminimum misalignment of the inlet and outlet of said chamber.

Other objects of this invention will appear in the fOl' lowingdescription and appended claim, reference being had to the accompanyingdrawings forming a part of this specification wherein like referencecharacters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a perspective view of a heat exchange unit embodying thepresent invention with the side cover removed.

FIGURE 2 is a mid-section taken on the line 2-2 in the direction of thearrows, FIGURE 1, but with certain external casing panels removed fromthe operative components.

FIGURE 3 is a fragmentary sectional view of a conventional prior art fanand chamber.

FIGURE 4 is a schematic view of a theoretical fan chamber design whichwould provide optimum air flow conditions.

Before explaining the present invention in detail, it

is to be understood that the invention is not limited in its applicationto the details of construction and arrangement of parts illustrated inthe accompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

Referring to the drawings and particularly FIGS. 1 and 2, there is shownan air moving unit of the present invention comprising a housing 10having an outside air opening 12, a room air opening 13, and a dischargeopening 14. The operative components of the unit are shown in FIG. 2,and include a back Wall 13, and a front wall 15 extending parallelthereto. Extending between walls 13 and 15 adjacent opposite endsthereof are two end walls, one of which is visible in FIG. 2, as at 17.The other end wall is not visible in the drawing; however it will beappreciated that it extends parallel with wall 17 but adjacent theopposite end portions of walls 13 and 15. The end walls are of coursespaced inwardly from the external end panel sections of the heatexchange device for accommodation of such structures as the fan-drivingmotor and the return bend portions of the heat exchange coils 16.

The fan of the FIG. 1 unit comprises a cylindrical fan rotor 26 having ashaft 28 suitably connected with the fan-driving motor to cause the fanto rotate in the arrow 29 direction. The fan comprises a series offorwardly curved blades 34 etxending through substantially the entiredistance between end wall 17 and the other end wall (not shown), thearrangement being such that the fluid is taken into the rotor along oneportion of its periphery and discharged from another portion of itsperiphery.

In operation of the FIG. 2 structure, the air is introduced into theunit through room air opening 13 and (if hinged damper 30 is Open)through outside air opening 12. The incoming air is directed through afilter 32 which preferably extends the entire distance between end Wall17 and the opposite end wall. The air then passes from filter 32upwardly around the drip pan 18 and through heat exchange coils 16, saidcoils having the usual fins 21 thereon for improved heat transfer, andthe coils and drip pan extending through the entire space between endwall 17 and the opposite end wall. The air is directed through the coils16 by a wall 22 which angles from wall 13 toward wall 15 to atermination point 27 located adjacent the rotor periphery. The spacebetween termination point 27 and point 31 on wall 15 defines an entrancethroat or opening 19 for the air as it is directed toward the rotor, thearrangement of walls 13, 15 and 22 cooperating with the end wall 17 andthe opposite end wall to define a relatively large inlet for the blowerunit.

Wall 15 extends upwardly from point 31 to a point 33, where it isconnected with an arcuate wall portion 24. It will be noted that thespacing between points 31 and 33 corresponds approximately with thediameter of fan rotor 26. Arcuate wall 24 thus forms a pocket 38 whichis located beyond the rotor 26 for causing the air to approach the rotorin a proper direction. In this connection it will be seen thatconnection point 33 is located in an imaginary plane 35 which extendsnormal to wall 15 and tangent to the rotor periphery at point 37. Thewall portion 24 bulges from point 33 in a substantial arc away from theentrance opening 25 and thence back toward the rotor periphery at 36 toa termination point 39. It will be noted that termination point 39extends in an imaginary plane 41 extending through point 27 and the axisof rotor 26. By this arrangement an entire one-half of the rotorperiphery is exposed to the incoming fluid. It will also be noted thatwall 15 is spaced from the periphery of rotor 26 by the distance 43,which is somewhat greater than the radius of the rotor. This arrangementcooperates with the disposition of arcuate wall portion 24 and entranceopening 19 to properly direct the incoming fluid into the rotor. Thus;as

the fluid passes from coils 16 a substantial portion thereof moves alongwall and then into the portion of pocket 38 adjacent wall portion 24.The air is then permitted to turn in the pocket as indicated by arrows45 so as to approach the rotor in the direction of rotor rotation. Acertain percentage of the air of course flows along wall 22 and thenceinto the rotor adjacent termination point 27. However, a substantialportion of the incoming air flows along walls 15 and 24 as indicatedabove so as to be properly received into the rotor. The large spacing at43 is of course instrumental in permitting the air to be received intothe pocket 38 and be turned around prior to its entry into the rotor.

The fluid is discharged from the rotor via an exit throat 25 defined 'bythe two laterally spaced outlet walls 47 and 49, end wall 17 and theopposite end wall (not shown). Wall 49 is connected with the inlet wall22 through a curved wall portion 51 which extends around a portion ofthe rotor periphery from termination point 27, the arrangement beingsuch that less than one-half of the rotor periphery is exposed to theexit throat.

The fan 26 produces a high ratio of velocity pressure to staticpressure. This is particularly true since the blades 34 are theforwardly curved type. The inlet adjacent the fan 26 is substantiallylarger than the outlet 25 to reduce inlet losses. In addition the pocket38 formed by wall 24 permits a large portion of the air to approach thefan 26 in a direction tangent to the rim of blades 34 as indicated bythe arrows in FIG. 2. It has been found that this is the best directionin which to introduce the air, and under no circumstances should anyappreciable portion of the air be introduced at an angle greater than aperpendicular to the tangent.

Theoretically, the most efiicient handling of the air would beaccomplished with the design shown in FIG. 4 wherein air is introducedthrough inlet 40 in the direction of travel of the fan 42 and isexpelled through outlet 44. Such a design is completely impractical forcommercial units such as air conditioners. The design of the presentinvention approaches the efiiciency of the theoretical design whilemaintaining the other characteristics necessary in a commercial unit.

Referring to a typical prior art fan and chamber construction as shownin FIG. 3, the air is taken in through inlet 112 and is expelled throughoutlet 114. It will be noted by the arrow indications at the lower rightin FIG. 3 that air entering the inlet 112 substantially opposite to thefan blade rotation isgiven an impact in nearly a reverse direction tothe direction of final flow. This causes severe energy losses andimpairs the efficient creation of proper static pressure.

From the foregoing description, it can be seen that I have devised anair moving unit which has an unusual pressure development ande'ificiency. There is good stability over all utilizable pressureranges. This improved structure has transformed a commercially abandonedline flow fan design into a device of substantial application.

Having thus described my invention, I claim:

The combination comprising acasing having first and second parallelwalls; a fan rotor located between said parallel walls and having arotational axis parallel thereto; a third wall angling from one of theparallel Walls toward but terminating in spaced relation to the otherparallel wall to define a restricted throat at the rotor; a fourth wallextending from the terminus of the third wall around a portion of therotor periphery and away therefrom to form one wall of an exit throat;said rotor having its periphery spaced a substantial distance from theother parallel wall to cooperate therewith in forming a passage from therestricted throat; a fifth arcuate wall starting from a point on saidother parallel wall located on an imaginary plane normal to said otherwall and tangent to the rotor periphery at a second point concealed fromthe first point, and extending in an arc bulging away from saidrestricted throat and then back toward said imaginary plane to a thirdpoint closely adjacent the second point whereby to form an axiallyextending pocket; a sixth wall angling from said third point toward saidother wall and away from the rotor to form another side of theaforementioned exit throat; said rotor being turnable in a directionfrom the aforementioned second point toward said other wall and beingbladed to draw fluid in the direction of its rotation, the arrangementof said fifth wall and the spacing between the rotor and said other wallcooperating whereby entering fluid is caused to travel along said otherwall and fifth wall so as to turn and approach the periphery of therotor in the direction of rotor rotation.

References Cited in the tile of this patent UNITED STATES PATENTS507,445 Mortier Oct. 24, 1893 1,823,579 Anderson Sept. 15, 19312,033,273 Buck Mar. 10, 1936 2,580,535 Feinberg Ian. 1, 1952 FOREIGNPATENTS 242,076 Germany ll Dec. 22, 1911 288,312 Germany Oct. 27, 1915807,978 Germany July 9, 1951

